Bearings

ABSTRACT

A bearing includes a first member having a passageway configured to engage a shaft, the first member having a metallic material; and a second member disposed around at least a portion of the first member, the second member having a metallic material and at least one radially and inwardly bent portion capable of restricting axial movement of the first member. The first and second members are movable relative to each other.

RELATED APPLICATIONS

This application claims benefit of U.S. Provisional Patent ApplicationSer. No. 61/043,529, titled “BEARINGS” filed Apr. 9, 2008 and claimsbenefit of U.S. Provisional Patent Application Ser. No. 61/043,554,titled “BEARING GREASE COMPOSITION” filed Apr. 9, 2008. Bothapplications are hereby incorporated by reference herein.

TECHNICAL FIELD

The invention relates to bearings and, in particular, toself-lubricating bearings.

BACKGROUND

Bearings can provide convenient means for rotatably, pivotably orslidably fastening multiple members to one another in a low maintenancemanner. Applications for bearings include those that have continuousrotational movement, such as journals for supporting a driven shaft.Bearings can also be used for applications that have repeated pivotalmovement, such as automotive door hinges, door checks, brake andaccelerator pedals. Additional applications include those that haverepeated reciprocal movement, such as automotive shock absorbers andstruts. Bearings can also be used in lighter duty applications, such asmultiple bar linkages used in the automotive industry for trunk deck lidand hood hinges. Low maintenance bearings can include a variety ofconfigurations, such as, for example, bushes or journal bearings, thrustbearings or washers, locating pads, valve port plates, and wearingcomponents for a variety of mechanisms. An example of a low maintenancea sliding bearing includes a metal support and a plastic layer.

SUMMARY

In one aspect, the invention features bearings, related methods, andsystems including the bearings. The bearings can be used in a variety ofhigh speed applications including high speed motors. The bearings mayprovide reduced motor vibrations, which can result in quieter motoroperation and increased motor life.

In one aspect, the invention features a bearing comprising an inner ringhaving a passageway configured to engage a shaft, the inner ring havingan inner surface and an outer surface, an outer ring disposed around atleast a portion of the inner ring, the outer ring having an innersurface and an outer surface, the outer ring comprising a polymer andforming a bearing surface at an interface with the inner ring whereinthe inner surface of the outer ring has a radius that is greater at themidline of the outer ring than at the lateral edges of the outer ring;and a hollow cylindrical ring surrounding and fixed to the outer ringwherein the inner ring is rotatable in relation to the hollowcylindrical ring.

In another aspect, the invention features a bearing, including a firstmember having a passageway configured to engage a shaft, the firstmember including a metallic material; and a second member disposedaround at least a portion of the first member, the second memberincluding a polymer and at least one radially and inwardly bent portioncapable of restricting axial movement of the first member. The first andsecond members are movable relative to each other.

Embodiments may include one or more of the following features. The firstmember consists essentially of a metallic material. The bearing furtherincludes a lubricant between the first member and the second member. Atleast one of the first member or the second member includes a cavitycontaining the lubricant. The second member further includes a polymer.The first member includes a groove extending along a circumferentialportion of the first member, and the second member includes a featureconfigured to engage with the groove and prevent axial movement of thefirst and second members relative to each other. The bearing furtherincludes a third member disposed around at least a portion of the secondmember, the third member including a metallic material. The third memberincludes at least one radially and inwardly bent portion capable ofrestricting axial movement of the first member.

In another aspect, the invention features a bearing including a firstmember having a passageway configured to engage a shaft, the firstmember consisting essentially of a metallic material; a second memberdisposed around at least a portion of the first member, the secondmember comprising a polymer and at least one radially and inwardly bentportion capable of restricting axial movement of the first member,wherein the first and second members are movable relative to each other;and a third member disposed around at least a portion of the secondmember, the third member including a metallic material and at least oneradially and inwardly bent portion capable of restricting axial movementof the first member.

Embodiments may include one or more of the following features. Thesecond member includes a first layer including the metallic material,and a second layer including a polymer. The bearing further includes alubricant between the first and second members.

In another aspect, the invention features a method including engagingthe passageway of a bearing described herein with a shaft of a motor,and moving the shaft, wherein a first member of the bearing moves withthe shaft and relative to a second member of the bearing.

In another aspect, the invention features a system, including a movableshaft; and a bearing including a first member having a passagewayconfigured to engage a shaft, the first member including a metallicmaterial; and a second member disposed around at least a portion of thefirst member, the second member including a polymer and at least oneradially and inwardly bent portion capable of restricting axial movementof the first member. The first and second members are movable relativeto each other.

Embodiments may include one or more of the following features. The firstmember consists essentially of a metallic material. The system furtherincludes a lubricant between the first member and the second member. Atleast one of the first member or the second member includes a cavitycontaining the lubricant. The second member further includes a polymer.The first member may include a groove extending along a circumferentialportion of the first member, and the second member includes a featureconfigured to engage with the groove and prevent axial movement of thefirst and second members relative to each other. The system furtherincludes a third member disposed around at least a portion of the secondmember, the third member including a metallic material. The third memberincludes at least one radially and inwardly bent portion capable ofrestricting axial movement of the first member. The system includes amotor having the shaft, and wherein the shaft is rotatable about itslong axis.

Other aspects, features and advantages will be apparent from thedescription of the embodiments thereof and from the claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram of a system including a motor and abearing.

FIG. 2 is a perspective view of an embodiment of a bearing.

FIG. 3 is a perspective, cut-away view of the bearing shown in FIG. 2.

FIG. 4 is a perspective view of a portion of an embodiment of a bearing.

FIG. 5 is a perspective view of a portion of an embodiment of a bearing.

FIG. 6 is a perspective, cut-away view of an embodiment of a bearing.

FIG. 7 is a perspective, cut-away view of an embodiment of a bearing.

FIG. 8 is a detailed, cross-sectional view of an embodiment of abearing.

FIG. 9 is an isometric view of an embodiment of a bearing.

FIG. 10 is a cutaway exploded view of the embodiment shown in FIG. 9.

FIG. 11 is a cross-sectional diagram of the embodiment shown in FIG. 9.

DETAILED DESCRIPTION

Referring to FIG. 1, a system 20 includes a housing 22, a motor 24having a rotor 26, at least a portion of which is in the housing, andbearing 28 in the housing. Rotor 26 includes a shaft capable of rotatingabout its longitudinal axis L, and bearing 28 is positioned between therotor and the housing. Bearing 28 is capable of reducing motorvibrations, which can result in quieter motor operation and increasedmotor life. In some embodiments, bearing 28 is used to replace bushingsand ball bearings in electric motors, e.g., high speed motors operatingat approximately 1,000-6,000 RPM or more and under loads ofapproximately 0-300 pounds.

As shown in FIGS. 2 and 3, bearing 28 includes an assembly of threeparts: a first member (as shown, a cylinder 30), a second member (asshown, a first flanged cylinder 32) surrounding the first member, and athird member (as shown, a second flanged cylinder 34 although thismember can also be an unflanged cylinder that surrounds double flangedcylinder 32) surrounding the second member. As shown, cylinder 30 is asolid and continuous member having an inner surface 36 and an outersurface. Inner surface 36 defines a passageway 38 that extends along thelongitudinal axis L′ of cylinder 30 (and bearing 28). The shape and sizeof passageway 38 are configured to allow cylinder 30 to be engaged with(e.g., pressed on to) rotor 26, resulting in an interferenc fit. Duringoperation of motor 24, as rotor 26 rotates about its longitudinal axisL, cylinder 30 rotates along with the rotor as a result of theinterference fit. The outer surface of cylinder 30 defines a cylindricalsurface. Cylinder 30 can include (e.g., be formed of) any materialincluding a metal, e.g., a pure metal (such as aluminum and magnesium)or an alloy (such as hardened steel), or a hard plastic. Cylinder 30 canbe formed, for example, by machining, forming from a strip, and/orextrusion.

First flanged cylinder 32 provides a bearing surface for cylinder 30 ascylinder 30 rotates during operation of motor 24. As shown, firstflanged cylinder 32 extends along the length of cylinder 30 andsurrounds at least a portion of the outer surface of cylinder 30. Firstflanged cylinder 32 has an inner surface and an outer surface, both ofwhich define cylindrical surfaces. The inner surface of first flangedcylinder 32 is in circumferentially sliding engagement with the outersurface of cylinder 30. In some embodiments, the clearance between theinner surface of first flanged cylinder 32 and the outer surface ofcylinder 30 is typically approximately 0.0005-0.003 inch (0.013˜0.076mm). As a result, during operation of motor 24, cylinder 30 rotatesalong with rotor 26, but first flanged cylinder 32 remains stationary.Still referring to FIG. 2, at a first end, first flanged cylinder 32 isflushed with an end of cylinder 30, and at an opposite second end, thefirst flanged cylinder includes a flange 40 configured to restrict axialmovement of cylinder 30. As shown, flange 40 is a radially and inwardlybent portion that extends along the thickness of cylinder 30 but doesnot extend into passageway 38. The clearance between flange 40 and anend wall of cylinder 30 can be approximately 0.005-0.010 inch(0.127˜0.254 mm). First flanged cylinder 32 can include (e.g., be formedof) any bearing material including a metal, e.g., a pure metal (such asaluminum and magnesium), an alloy (such as hardened steel), or acomposite (e.g., Norglide Pro® material having a steel or aluminumsubstrate and a PTFE layer laminated to the substrate). Othermaintenance free bearing materials, e.g. NORGLIDE® M, SM or T, can beused. First flanged cylinder 32 can be formed, for example, by rolling astrip of material and flanging the roll by conventional techniques.

Second flanged cylinder 34 is configured to hold cylinder 30 and firstflanged cylinder 32 within housing 22. As shown, second flanged cylinder34 extends along the length of first flanged cylinder 32 and surroundsat least a portion of the outer surface of first flanged cylinder 32.First flanged cylinder 32 has an inner surface and an outer surface,both of which define cylindrical surfaces. At a first end, secondflanged cylinder 34 is flush with an end of cylinder 30, and at a secondopposite end, the second flanged cylinder includes a flange 42configured to restrict axial movement of cylinder 30. The clearancebetween flange 42 and an end wall of cylinder 30 can be approximately 0to 0.01 inch (0˜0.254 mm). As shown, flange 42 is a radially andinwardly bent portion that extends along the thickness of first flangedcylinder 32 and cylinder 30 but does not extend into passageway 38.Second flanged cylinder 34 can include (e.g., be formed of) any hardmaterial including a metal, e.g., a pure metal (such as aluminum andmagnesium) or an alloy (such as hardened steel). Second flanged cylinder34 can be formed, for example, by rolling a strip of material andflanging the roll by conventional techniques.

Bearing 28 can be formed by forming the three parts described above(cylinder 30, first flanged cylinder 32, and second flanged cylinder 34)and assembling the parts together. For example, cylinder 30 can be slidinto first flanged cylinder 32, and these two parts can be slid intosecond flanged cylinder 34 to form bearing 28. Axial movement ofcylinder 30 is restricted by first and second flanged cylinder 32, 34.

In use, bearing 28 can be placed in a housing or a space configured toreceive the bearing, and a member (e.g., a shaft of a motor) can beplaced in engagement with passageway 38 of the bearing. When the membermoves (e.g., rotates), cylinder 30 of bearing 28 moves with the memberand bears against first flanged cylinder 32.

While a number of embodiments have been described, the invention is notso limited.

For example, while passageway 38 is shown above has having a circularcross section, in other embodiments, the passageway has a non-circularcross section, such as oval, elliptical, regularly or irregularlypolygonal having three, four, five, six, seven, eight or more sides. Themember (e.g., rotating shaft) configured to engage with passageway 38would have a cross section with a correspondingly matching outer contourto provide the interference fit or engagement for operation, asdescribed herein.

As another example, in some embodiments, the wall(s) of first and/orsecond flanged cylinders 32, 34 include a slit or a gap extendingparallel to longitudinal axis L′. After the parts of the bearing areassembled, the opposing parts of the slit can be joined together (e.g.,by welding or by interlocking features) or remained spaced.

Referring to FIG. 4, to further reduce axial movement of the parts,cylinder 30 can include one or more grooves 50 extending wholly orpartially about its outer circumferential surface, and first flangedcylinder 32 can include one or more complementary features 51 (e.g., araised segment) configured to engage with the groove. Similarly, theouter surface of first flanged cylinder 32 and the inner surface ofsecond flanged cylinder 34 can include similar complementary features toprevent axial movement of these parts.

In some embodiments, the bearings described herein are used inapplications in which a pivotable member (e.g., a shaft) is placed inthe passageway of the bearings.

In some embodiments, the bearings described herein include one or morelubricants or lubricious layers between cylinder 30 and first flangedcylinder 32. The lubricant or lubricious layer can enhance the wearresistance of the bearings. Examples of materials included in thelubricant or lubricious layer include solid state materials (e.g.,inorganic materials such as graphite and/or molybdenum disulfide),viscous fluids (e.g., grease), polymers (e.g., fluoropolymers (such asPTFE) and/or silicone), and combinations thereof. Referring to FIG. 5,the outer surface of cylinder 30 and/or the inner surface of firstflanged cylinder 32 can include one or more cavities 54 (e.g., pocketsand/or grooves) that serve as reservoirs for the lubricant.

One or more additives can be included in the lubricant or lubriciouslayer, for example, to enhance thermal conductivity and to dissipateheat that can be generated during use. An example of an additive ismetal particles, e.g., bronze particles.

The bearing members can include one or more intermediate layers betweenmetallic and polymer layers. The intermediate layer can, for example,enhance adhesion or bonding of the polymer to the metallic substrate.The intermediate layer can include, for example, an adhesive such asfluoropolymers including PFA, MFA, ETFE, FEP, PCTFE, and PVDF, curingadhesives such as epoxy, polyimide adhesives, and lower temperature hotmelts such as ethylene vinylacetate (EVA) and polyether/polyamidecopolymer (Pebax®).

While bearing 28 as shown in FIGS. 2 and 3 includes three components, inother embodiments, the bearing includes two components or more thanthree components. FIG. 6 shows an exemplary two-component bearing 28′including a first member (as shown, cylinder 30) and a second member (asshown, first flanged cylinder 32′) surrounding the first member. At itsends, first flanged cylinder 32′ includes a first flange 40′ and asecond flange 40″ configured to restrict axial movement of cylinder 30.Flanged cylinder 32′ may be a split cylinder that includes two ends thatmay be joined, for example, by welding, by adhesive bonding, with aconnector, or through interlocking tabs and slots. The materials used tofabricate bearing 28′, as well as the clearances between the components,can be the same as described above for bearing 28. Bearing 28′ caninclude one or more of the features described above (e.g., differentcross-sectional shapes, lubricants, additional layers, grooves). Bearing28′ may optionally include a third component that surrounds thecircumference of double flanged cylinder 32′. This third component maybe void of flanges and may help to stabilize the bearing and keep it inround. The third component may be metallic and/or polymeric and may beshaped and sized to fit a specific housing or other application. It maybe cylindrical or other shape such as a regular polygon. The innersurface of the third component may present a different shape than theouter surface. It may be friction fit or adhered to flanged cylinder32′.

As another example, FIG. 7 shows a bearing 28″ including a first member(as shown, cylinder 30), a two-component second member (as shown, firstflanged cylinder 32″) surrounding the first member, and a third member(as shown, cylinder 50) surrounding the second member. Flanged cylinder32″ includes two parts 33, 33′ that, respectively, have flanges 35, 35′configured to restrict axial movement of cylinder 30. Parts 33, 33′ maybe in axial contact with each other or may be axially spaced from eachother to define a gap 52, for example, approximately 0.002 inch (0.05mm) to approximately 0.010 inch (0.254 mm) long. As shown, cylinder 50is a continuous cylinder with no flanges and can be formed of, forexample, steel or aluminum. It is believed that cylinder 50 providesbearing 28″ with stiffness and consistent clearances between thecomponents of the bearing. The materials used to fabricate bearing 28″,as well as the clearances between the components, can be the same asdescribed above for bearing 28.

Bearing 28″ can include one or more of the features described above(e.g., different cross-sectional shapes, lubricants, additional layers,grooves). For example, FIG. 8 shows a bearing 28′″ including firstmember cylinder 30, first flanged cylinder 32″ (second member)surrounding the first member, and cylinder 50 surrounding the secondmember. First flanged cylinder 32″ includes two symmetrical halves 33and 33′. As shown, first flanged cylinder 32″ includes a metal substrate59 and a polymer layer 60 on the metal substrate. Examples of materialsfor first flanged cylinder 32″ include a metal substrate (e.g., a steelor aluminum substrate) and a polymer layer (e.g., a PTFE layer)laminated to the substrate (e.g. NORGLIDE® M, SM T, Pro®). In someembodiments, bearing 28′″ includes a lubricant between cylinder 30 andfirst flanged cylinder 32″, and as shown the first flanged cylinderincludes a cavity 62 in polymer layer 60 near gap 52 to help retain thelubricant. Cavity 62 in polymer layer 60 may be present with or withoutgap 52. One specific example of an appropriate lubricant is a lubricantcomposition including (by volume) 62% Mobil 1® 0W-40 motor oil, 19%Bakoda® ski wax and 19% Lucas® Heavy Duty Oil Stabilizer. Examples ofadditional lubricants are described in the patent application titledBEARING GREASE COMPOSITION, Attorney Docket No. 0-5056, filed on evendate herewith and which is hereby incorporated by reference herein. Inother embodiments, bearing 28′″ does not include the lubricant and/orcavity 62.

Other embodiments may include four or more components. An exemplarybearing having more than three components can include a first member(e.g., cylinder 30), a second member (e.g., first flanged cylinder 32)surrounding the first member, a third member (e.g., second flangedcylinder 34) surrounding the second member, and additional members(e.g., one, two, three or more) surrounding the third member. Theadditional members can surround the more radially inward memberssimilarly to how the second member or the third member surrounds moreradially inward member(s).

Another example is provided in FIGS. 9-11 which show an assembledbearing 88 in an isometric view (FIG. 9), in cutaway exploded view (FIG.10) and in cross-sectional view (FIG. 11). In this embodiment thecylindrical members may be in the form of V-shaped (cross-sectionalprofile) rings. This embodiment includes inner V-shaped ring 36 whichcan slidably rotate with respect to outer V-shaped ring 38. OuterV-shaped ring 38 may be permanently fixed to hollow cylindrical ring 80.In similar embodiments the inner and outer rings may include differentprofiles that are not specifically V-shaped. For example, thecross-sectional profile of the inner ring may be U-shaped. This profilecan allow for a concave outer surface (of the inner ring) structure thatresults in one or more substantial bearing surfaces that are notparallel to the radial axis of the bearing. This is in contrast, forexample, to the bearing shown in FIG. 7 in which the majority of thebearing surface is parallel to the radial axis of the bearing. Theradius of the inner ring and/or outer ring may be greater toward thecenter (midline) of the bearing than it is at the lateral edges of thebearing. Moving from the outer edge to the center of the bearing, theradius may increase linearly, as in the case of a V-shaped inner ring oraccording to the equation of a curve in the case of a U-shaped ring. Insome cases it may be only the outer surface of inner ring 36 and theinner surface of outer ring 38 that exhibit this increasing radius. Forexample, inner ring 36 may be formed so that it fills space 89 whilemaintaining a V-shaped profile on the outer surface. In this case, theinner surface of the inner ring may be parallel to the radial axis ofthe bearing while the outer surface is not parallel to the radial axisof the bearing.

Inner V-shaped ring 36 may be formed from a single piece or frommultiple components as shown in FIG. 10. If a multi-component innerV-shaped ring is chosen, the components may remain separate or may bepermanently attached together. For example, complementary halves may bejoined together at central line 96 to form a unitary inner V-shapedring. The inner V-shaped ring may be, for example, metallic or ametallic alloy and may include, for instance, steel or bronze. As seenin FIGS. 10 and 11, inner V-shaped ring 36 may include two substantiallystraight inner surfaces (in cross section) 36 a and 36 b that form a “V”by sloping outwardly as they meet centrally in the bearing. InnerV-shaped ring 36 may include a flattened portion 36 d at one or both ofthe outer edges of the ring. When inner V-shaped ring 36 receives ashaft 90 (shown in dotted lines), flattened portion 36 d may be the onlyportion of inner V-shaped ring 36 that is in contact with the shaft.Thus when shaft 90 is installed it may be supported by flattened portion36 d and may form a space 89 between the surface of the shaft and the Vportion of the inner surface 36 a and 36 b of the inner V-shaped ring.Space 89 can reduce heat transfer between the bearing and the shaftwhich can, for example, result in a cooler operating motor.

Inner surface 38A of outer V-shaped ring 38 may be complementary toouter surface 36 c of inner V-shaped ring 36. Outer V-shaped ring 38 mayinclude outer flattened portions that correspond to flattened portions36 d of inner V-shaped ring 36. Outer V-shaped ring 38 can be acomposite and may include a fluoropolymer or other self-lubricatingmaterial on inner surface 38 a that is laminated to a metallic substrateto form the composite ring. For example, outer V-shaped ring 38 may beformed from NORGLIDE® M, SM, T, or Pro® as described above. OuterV-shaped ring 38 may be a single piece or may include two or more piecesjoined together. In one embodiment, as shown, two symmetrical halves canbe spot welded together. By spot welding, the joint between the twohalves may form intermittent passages that allow lubricant to pass fromcavity 87 to the bearing surfaces between the inner and outer V-shapedrings. In other cases the seam between the two halves may be completelysealed.

Hollow cylindrical ring 80 may form a housing for bearing 88. Hollowcylindrical ring 80 may be formed from a metallic material such assteel. Hollow cylindrical ring 80 can include two L-shaped (incross-section) cylindrical rings that may be joined together by, forexample, welding, press fitting or overmolding with a polymer. Forinstance, laser spot weld 84 can be seen in FIG. 9. Outer V-shaped ring38 can be fixed to hollow cylindrical ring 80 by spot welding or othertechniques. Spot welds 86 a, 86 b and 86 c are evident in FIG. 9 andserve to affix hollow cylindrical ring 80 to outer V-shaped ring 38,thus immobilizing hollow cylindrical ring 80 with respect to outerV-shaped ring 38. As a result, inner V-shaped ring 36 is slidablyrotatable in relation to both outer V-shaped ring 38 and hollowcylindrical ring 80. Hollow cylindrical ring 80 can be dimensioned toform cavity 87 that is a substantially toroidal shape and that extendsaround the outer surface 38 b of outer V-shaped ring 38. “Substantiallytoroidal” means that the cavity extends 360 degrees around the bearingbut (as shown) it need not have a circular or even a roundedcross-section. Inclusion of this cavity has been found to reducevibration and provide quieter operation as well as provide greatertolerance regarding the angle of the shaft that is supported by bearing88. For example, “edge loading” that can result from a bent shaft can bemore readily tolerated with the V-shape than it can with flat surfacedcylindrical bearings. The size of cavity 87 may be extended by enlargingthe axial walls 92 of hollow cylindrical ring 80. Cavity 87 may be emptyor may contain an additional component such as a lubricant or dampingmaterial. For example, cavity 87 may be filled, at least partially, withone of the greases or other lubricants described or referred to herein.The lubricant can be passively supplied to the bearing surfaces throughpassages formed in outer V-shaped bearing 38.

Hollow cylindrical ring 80 may be coated partially or totally with anelastomer to produce an elastomer coated metal. For instance, anelastomeric coating may be applied to axial surface 92 or to cylindricalsurface 94, or to both. The elastomeric coating can help to provideadditional vibration and noise reduction as well as provide for easierand more secure fitting of the bearing in a device. Appropriate coatingsmay include, for example, natural and synthetic elastomers such as PVC,PVB and NBR (nitrile rubber).

When used to rotatably support a shaft, such as a shaft of a motor or asteering mechanism, bearing 88 may be particularly tolerant of thrustloading that may cause extensive wear in alternative bearings. If anaxial force is applied to the bearing through the shaft, this axialforce is spread across substantially one half (the outer half) of thetotal contacting surfaces of the V-shaped bearing. In flanged bearingsthat include a substantially flat portion (in cross-section) from flangeto flange, the force from the thrust loading may be applied almostentirely to the flange, resulting in excessive friction and wear at theflange location. It has been found that by spreading this force acrossthe outer half of the V-shaped surface, rather than entirely to theflange, the frictional wear can be significantly reduced.

While several embodiments of the present invention have been describedand illustrated herein, those of ordinary skill in the art will readilyenvision a variety of other means and/or structures for performing thefunctions and/or obtaining the results and/or one or more of theadvantages described herein, and each of such variations and/ormodifications is deemed to be within the scope of the present invention.More generally, those skilled in the art will readily appreciate thatall parameters, dimensions, materials, and configurations describedherein are meant to be exemplary and that the actual parameters,dimensions, materials, and/or configurations will depend upon thespecific application or applications for which the teachings of thepresent invention is/are used. Those skilled in the art will recognize,or be able to ascertain using no more than routine experimentation, manyequivalents to the specific embodiments of the invention describedherein. It is, therefore, to be understood that the foregoingembodiments are presented by way of example only and that, within thescope of the appended claims and equivalents thereto, the invention maybe practiced otherwise than as specifically described and claimed. Thepresent invention is directed to each individual feature, system,article, material, kit, and/or method described herein. In addition, anycombination of two or more such features, systems, articles, materials,kits, and/or methods, if such features, systems, articles, materials,kits, and/or methods are not mutually inconsistent, is included withinthe scope of the present invention.

All definitions, as defined and used herein, should be understood tocontrol over dictionary definitions, definitions in documentsincorporated by reference, and/or ordinary meanings of the definedterms.

The indefinite articles “a” and “an,” as used herein in thespecification and in the claims, unless clearly indicated to thecontrary, should be understood to mean “at least one.”

The phrase “and/or,” as used herein in the specification and in theclaims, should be understood to mean “either or both” of the elements soconjoined, i.e., elements that are conjunctively present in some casesand disjunctively present in other cases. Other elements may optionallybe present other than the elements specifically identified by the“and/or” clause, whether related or unrelated to those elementsspecifically identified, unless clearly indicated to the contrary.

All references, patents and patent applications and publications thatare cited or referred to in this application are incorporated in theirentirety herein by reference.

1. A bearing, comprising: an inner ring having a passageway configuredto engage a shaft, the inner ring having an inner surface and an outersurface; an outer ring disposed around at least a portion of the innerring, the outer ring having an inner surface and an outer surface, theouter ring comprising a polymer and forming a bearing surface at aninterface with the inner ring wherein the inner surface of the outerring has a radius that is greater at the midline of the outer ring thanat the lateral edges of the outer ring; and a hollow cylindrical ringsurrounding and fixed to the outer ring wherein the inner ring isrotatable in relation to the hollow cylindrical ring.
 2. The bearing ofclaim 1 comprising a substantially flat portion on lateral edges of theinner surface of the inner ring wherein the flat portion is parallel tothe axis of rotation of the bearing and is constructed and arranged toreceive and contact a cylindrical shaft.
 3. The bearing of claim 1wherein the cross-sectional profile of at least a portion of the innersurface of the outer ring is V-shaped.
 4. The bearing of claim 1 whereinthe cross-sectional profile of at least a portion of the inner surfaceof the outer ring is U-shaped.
 5. The bearing of claim 1 wherein theinner surface of the inner ring forms a substantially toroidal cavitywith a cylindrical shaft when the cylindrical shaft is engaged with thebearing.
 6. The bearing of claim 1 wherein the outer ring comprises ametal/polymer composite.
 7. The bearing of claim 6 wherein the innersurface of the outer ring comprises a polymer layer.
 8. The bearing ofclaim 7 wherein the polymer layer comprises PTFE.
 9. The bearing ofclaim 1 wherein the outer ring is comprised of two symmetrical portionsjoined at the midline of the ring.
 10. The bearing of claim 1 whereinthe outer ring includes one or more passageways providing fluidcommunication between the hollow cylinder and the outer surface of theinner ring.
 11. The bearing of claim 1 wherein the hollow cylindricalring defines a substantially toroidal space between an inner surface ofthe hollow cylindrical ring and the outer surface of the outer ring. 12.The bearing of claim 11 wherein a lubricant is retained in thesubstantially toroidal space.
 13. The bearing of claim 11 wherein adampening insulator is retained in the substantially toroidal space. 14.The bearing of claim 1 wherein the hollow cylindrical ring comprises anelastomeric coating.
 15. The bearing of claim 14 wherein the elastomericcoating is on the outer surface of the hollow cylindrical ring.
 16. Abearing, comprising: a first member having a passageway configured toengage a shaft, the first member comprising a metallic material; and asecond member disposed around at least a portion of the first member,the second member comprising a polymer and at least one radially andinwardly bent portion capable of restricting axial movement of the firstmember, wherein the first and second members are movable relative toeach other. 17-35. (canceled)
 36. A bearing, comprising: a first memberhaving a passageway configured to engage a shaft, the first memberconsisting essentially of a metallic material; a second member disposedaround at least a portion of the first member, the second membercomprising a polymer and at least one radially and inwardly bent portioncapable of restricting axial movement of the first member, wherein thefirst and second members are movable relative to each other; and a thirdmember disposed around at least a portion of the second member, thethird member comprising a metallic material and at least one radiallyand inwardly bent portion capable of restricting axial movement of thefirst member.
 37. The bearing of claim 36, wherein the second membercomprises a first layer comprising the metallic material, and a secondlayer comprising a polymer.
 38. The bearing of claim 36, furthercomprising a lubricant between the first and second members.
 39. Thebearing of claim 36 further comprising a fourth member circumferentiallysurrounding at least a portion of the third member. 40-67. (canceled)